This invention is directed to the art of electroforming in which a smooth surface of nickel cobalt or nickel-cobaltalloy is formed on a conductive substrate (mandrel) from an electrolyte for nickel or cobalt. Typical baths are formed from the acids and their nickel and/or cobalt salts to include sulfamic acid, sulfuric acid, hydrochloric acid, hydrobromic acid, methanesulfonic acid, fluoboric acid, pyrophosphoric acid, and mixtures with or without boric acid and/or acetic acid. A typical bath is formed of a nickel sulfamate solution comprising about 10 to 16 oz/gal total nickel, about 0.9 to 4.5 oz/gal halide as NiX.sub.2.6H.sub.2 O and about 4.5 to 6.0 oz/gal H.sub.3 BO.sub.3. Such baths are normally maintained at a temperature of between about 135.degree.F and about 160.degree.F at an ultimate current density of between about 200 and about 600 ASF (amperes per square foot). At the start of electrodeposition, the current density normally increases to its ultimate value within about 5 seconds. Because of the relatively high current density and various contaminants in the bath, it has been difficult to form a nickel surface which is sufficiently smooth to be useful as a photoreceptive substrate in an electrostatographic copying machine. For best results, the outside surfaces of these nickel foil cylinders ("belts") should have a surface roughness not more than about 50 microinches, arithmetic average (AA). Surface roughness as used herein is determined by the standard set forth by the American Society of Mechanical Engineers ASA B46.1 - 1962. Unfortunately, however, belts commonly produced under the optimum aforesaid conditions may have a surface roughness of up to 80 microinches AA. It is to this problem to which this invention is directed.